Outdoor unit of refrigeration cycle apparatus

ABSTRACT

An outdoor unit of a refrigeration cycle apparatus to be installed in an external-wall internal space of a structure includes a casing, a heat exchanger accommodated in the casing, a first air-sending device configured to cause air to pass through the heat exchanger and discharge the air to the external-wall internal space, a second air-sending device configured to suck the air discharged to the external-wall internal space by the first air-sending device and discharge the air to an outside of the structure, and a divider that divides an inside of the casing into a first air passage and a second air passage. The heat exchanger and the first air-sending device are disposed in the first air passage. The second air-sending device is disposed in the second air passage.

CROSS REFERENCE TO RELATED APPLICATION

This application is a U.S. national stage application of InternationalApplication No. PCT/JP2015/085586, filed on Dec. 18, 2015, the contentsof which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a wall-embedded outdoor unit of arefrigeration cycle apparatus to be installed in an external wall of astructure, such as a building.

Background

Examples of wall-embedded outdoor units of a refrigeration cycleapparatus known in the art disclosed in Patent Literature 1 include anair-conditioning outdoor unit having an air inlet and an air outletarranged on the same surface of a main body such that the air outlet islocated above the air inlet. The outdoor unit disclosed in PatentLiterature 1 includes a heat exchanger and an air-sending device locatedabove the heat exchanger. The outdoor unit is configured such that airsucked into the air inlet by driving the air-sending device is subjectedto heat exchange in the heat exchanger and is then blown from the airoutlet by the air-sending device. In other words, the outdoor unitdisclosed in Patent Literature 1 is configured such that the air blownfrom the air outlet and the air sucked into the air inlet flow inopposite directions.

PATENT LITERATURE

Patent Literature 1: Japanese Unexamined Patent Application PublicationNo. 3-213928

The outdoor unit disclosed in Patent Literature 1 is provided with anair passage inside the outdoor unit such that the air sucked into theair inlet is directed in an opposite direction and is then blown fromthe air outlet. Such a configuration increases aerodynamic resistance toair flowing inside the outdoor unit. The increase in aerodynamicresistance results in an increase in noise inside the outdoor unit.Disadvantageously, the outdoor unit disclosed in Patent Literature 1fails to ensure quietness. To improve the air-sending performance of theair-sending device in the outdoor unit disclosed in Patent Literature 1,the air-sending device has to be increased in size. To improve the heatexchange performance of the heat exchanger in the outdoor unit disclosedin Patent Literature 1, the heat exchanger has to be increased in size.Consequently, it is difficult to achieve both reduction in size of theoutdoor unit and improvement in performance of the outdoor unit.

SUMMARY

The present invention aims to overcome the above-described disadvantagesand aims to provide an outdoor unit of a refrigeration cycle apparatuscapable of ensuring quietness and achieving both reduction in size ofthe outdoor unit and improvement in performance of the outdoor unit.

An embodiment of the present invention provides an outdoor unit of arefrigeration cycle apparatus to be installed in an external-wallinternal space of a structure. The outdoor unit includes a casing, aheat exchanger accommodated in the casing, a first air-sending deviceconfigured to cause air to pass through the heat exchanger and dischargethe air to the external-wall internal space, a second air-sending deviceconfigured to suck the air discharged to the external-wall internalspace by the first air-sending device and discharge the air to anoutside of the structure, and a divider that divides an inside of thecasing into a first air passage and a second air passage. The heatexchanger and the first air-sending device are disposed in the first airpassage. The second air-sending device is disposed in the second airpassage.

According to an embodiment of the present invention, it is unnecessaryto provide an air passage for directing a flow of air subjected to heatexchange in an opposite direction inside the outdoor unit. Thus, theoutdoor unit can ensure quietness and can also be reduced in size.Furthermore, the flow of air subjected to heat exchange does notstagnate inside the outdoor unit, leading to improvement in performanceof the outdoor unit. Consequently, an embodiment of the presentinvention can provide the outdoor unit of a refrigeration cycleapparatus capable of ensuring quietness and achieving both reduction insize of the outdoor unit and improvement in performance of the outdoorunit.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic front view illustrating an exemplary structure ofan outdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 1 of the present invention.

FIG. 2 is a schematic rear view illustrating the exemplary structure ofthe outdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 1 of the present invention.

FIG. 3 is a schematic diagram illustrating an installed state of theoutdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 1 of the present invention in an external wall 25 of abuilding.

FIG. 4 is a schematic diagram illustrating an installed state of theoutdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 1 of the present invention in the external wall 25 of thebuilding and an installed state of an indoor unit 50 connected to theoutdoor unit 1 by a refrigerant pipe 45.

FIG. 5 is a schematic front view illustrating an exemplary structure ofan outdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 2 of the present invention.

FIG. 6 is a schematic rear view illustrating the exemplary structure ofthe outdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 2 of the present invention.

DETAILED DESCRIPTION Embodiment 1

An outdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 1 of the present invention will be described. FIG. 1 is aschematic front view illustrating an exemplary structure of the outdoorunit 1 of a refrigeration cycle apparatus according to Embodiment 1. Asillustrated in FIG. 1, the outdoor unit 1 is constructed as a thin-type,wall-embedded outdoor unit having a cuboidal appearance.

Note that the relative dimensions and shapes of components in thefollowing figures including FIG. 1 may differ from the actual relativedimensions and shapes of the components. In the following figures, thesame or similar components are denoted by the same reference signs, orthe reference signs for the same or similar components are omitted. Inthe following description, the positional relationship between thecomponents of the outdoor unit 1 in the front-rear direction, theleft-right direction, or the up-down direction, in principle, is thepositional relationship in a state where the outdoor unit 1 is placed inposition ready to be used. The term “front surface” of the outdoor unit1 refers to an outer surface positioned on an indoor side when theoutdoor unit 1 is installed on a wall of a structure such that theoutdoor unit 1 can be used. The term “rear surface” of the outdoor unit1 refers to an outer surface positioned on an outdoor side when theoutdoor unit 1 is installed on the wall of the structure such that theoutdoor unit 1 can be used. The term “left surface” or “right surface”of the outdoor unit 1 refers to a left outer surface or a right outersurface of the outdoor unit 1 when the outdoor unit 1 is viewed from thefront.

As illustrated in FIG. 1, the outdoor unit 1 includes a casing 1 a, afirst front panel 3, and a second front panel 5 such that the frontpanels are arranged on the front of the casing 1 a. The front panelsconstitute a front outer surface of the casing 1 a of the outdoor unit1. An internal space of the outdoor unit 1 is divided into left andright compartments by a first divider 7. The first front panel 3 isformed as a panel that covers the left compartment. The second frontpanel 5 is formed as a panel that covers the front of the rightcompartment. The first front panel 3 and the second front panel 5 arefixed by, for example, screws. The front panels can be formed as servicepanels that allow access to the inside of the outdoor unit 1 formaintenance. Each of the first front panel 3 and the second front panel5 is formed as, for example, a sheet metal panel.

The first front panel 3 has a first vent 9 a and second vents 9 b. Thefirst vent 9 a is disposed such that air inside the outdoor unit 1 canbe discharged to the outside by driving and rotating a first air-sendingdevice 11 a. Each of the second vents 9 b is disposed such that airoutside the outdoor unit 1 can be sucked into the outdoor unit 1 bydriving and rotating a second air-sending device 11 b. In FIG. 1, onefirst vent 9 a is disposed in lower part of the first front panel 3, andtwo second vents 9 b are horizontally aligned above the first vent 9 a.The first vent 9 a and the second vents 9 b can each have, for example,a circular shape that is the same as the shape of the opening of acorresponding one of rectifier bell mouths surrounding the firstair-sending device 11 a and the second air-sending devices 11 b. Each ofthe first vent 9 a and the second vents 9 b can be covered with aventilation cover. The rectifier bell mouths and the ventilation coversare not illustrated in the following figures including FIG. 1.

The first air-sending device 11 a and the second air-sending devices 11b are disposed in the left compartment of the internal space, divided bythe first divider 7, of the outdoor unit 1. The left compartment servesas an air-sending-device chamber. The left compartment, where the firstair-sending device 11 a and the second air-sending devices 11 b aredisposed, of the internal space of the outdoor unit 1 divided by thefirst divider 7 will be referred to as an air-sending-device chamber.Each of the first air-sending device 11 a and the second air-sendingdevices 11 b is constructed as an axial fan, such as a propeller fan.The first air-sending device 11 a and the second air-sending devices 11b are disposed so that, in the outdoor unit 1, the direction of an aircurrent produced by driving the first air-sending device 11 a isopposite to the direction of an air current produced by driving thesecond air-sending devices 11 b.

The right compartment of the internal space of the outdoor unit 1divided by the first divider 7 serves as a machine chamber. Asillustrated in, for example, FIG. 1, the machine chamber accommodates acompressor 13 serving as fluid machinery that compresses suckedlow-pressure refrigerant and discharges the refrigerant as high-pressurerefrigerant. The compressor 13 is constructed as, for example, a rotarycompressor or a scroll compressor. The machine chamber may accommodateother components included in the outdoor unit 1, for example, anaccumulator, an oil separator, a refrigerant flow switching device, aliquid receiver, and a pressure reducing device.

FIG. 2 is a schematic rear view illustrating the exemplary structure ofthe outdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 1. As illustrated in FIG. 2, a first rear panel 15, a secondrear panel 17, and a heat exchanger 19 are disposed on the rear of thecasing 1 a of the outdoor unit 1. These components constitute a rearouter surface of the casing 1 a of the outdoor unit 1. Theair-sending-device chamber of the outdoor unit 1 is divided into upperand lower compartments by a second divider 21. The first rear panel 15is formed as a panel that covers the upper compartment of theair-sending-device chamber. The lower compartment of theair-sending-device chamber accommodates the first air-sending device 11a and the heat exchanger 19 horizontally facing the first air-sendingdevice 11 a. The second rear panel 17 covers the machine chamber of theoutdoor unit 1. Each of the first rear panel 15 and the second rearpanel 17 is formed as, for example, a sheet metal panel fixed by, forexample, screws or soldering.

The first rear panel 15 has a plurality of air outlets 23. The airoutlets 23 are disposed so that the air sucked into the outdoor unit 1through the second vents 9 b can be discharged to the outside by drivingand rotating the second air-sending devices 11 b. In FIG. 2, two airoutlets 23 are horizontally aligned. Similarly to the second vents 9 b,the air outlets 23 can each have, for example, a circular shape that isthe same as the shape of the opening of the rectifier bell mouthsurrounding each of the second air-sending devices 11 b. Each of the airoutlets 23 can be covered with an outlet cover.

The heat exchanger 19 can be constructed as, for example, a finned-tubeheat exchanger including a plurality of fins arranged parallel to oneanother and heat transfer tubes extending through the plurality of fins.The heat exchanger 19 may be flat-shaped or may be U-shaped or L-shapedwhen the heat exchanger 19 is viewed from above. The heat exchanger 19acts as a condenser in a cooling operation in which cooling energy isprovided to, for example, an indoor unit connected to the outdoor unit1, and acts as an evaporator in a heating operation in which heatingenergy is provided to, for example, the indoor unit. The condenser maybe referred to as a radiator and the evaporator may be referred to as acooler when the refrigeration cycle apparatus is an air-conditioningapparatus.

The fan diameter of the first air-sending device 11 a is determined inconsideration of, for example, the outer dimensions of the heatexchanger 19. The fan diameter of each of the second air-sending devices11 b or the number of the second air-sending devices 11 b installed isdetermined so that air subjected to heat exchange in the heat exchanger19 can be discharged to the outside with a sufficient flow rate.

An installed state of the outdoor unit 1 of a refrigeration cycleapparatus according to Embodiment 1 will be described below withreference to FIGS. 3 and 4.

FIG. 3 is a schematic diagram illustrating an installed state of theoutdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 1 in an external wall 25 of a building. FIG. 4 is a schematicdiagram illustrating an installed state of the outdoor unit 1 of arefrigeration cycle apparatus according to Embodiment 1 in the externalwall 25 of the building and an installed state of an indoor unit 50connected to the outdoor unit 1 by a refrigerant pipe 45. FIGS. 3 and 4schematically illustrate an internal structure of the outdoor unit 1viewed from the left side of the outdoor unit 1.

As illustrated in FIG. 3, the external wall 25 of the building has anexternal-wall internal space 27 that is a recess opening to the outsideof the building. Specifically, the external-wall internal space 27 isformed in the external wall 25 of the building such that a wall 31 is atleast interposed between the external-wall internal space 27 and anindoor space 29. A grille 33 is attached to an opening of theexternal-wall internal space 27 such that the building has a goodappearance and ventilation can be achieved.

As illustrated in FIGS. 3 and 4, the outdoor unit 1 is disposed in theexternal-wall internal space 27 such that the front surface of thecasing 1 a of the outdoor unit 1 is directed toward the indoor space 29.As illustrated in FIG. 4, the wall 31 included in the external wall 25of the building has a maintenance door 35 so that the external-wallinternal space 27 is accessible to a service technician for the outdoorunit 1. As described above, the first front panel 3 or the second frontpanel 5 disposed on the front of the casing 1 a of the outdoor unit 1can be formed as a service panel. As the first front panel 3 or thesecond front panel 5 is formed as a service panel, the servicetechnician for the outdoor unit 1 can open the maintenance door 35 inthe indoor space 29, approach the outdoor unit 1, remove the servicepanel, and have access to the inside of the outdoor unit 1. As theservice panel is directed toward the indoor space 29, the servicetechnician can have access to the outdoor unit 1 from the indoor space29 and readily perform maintenance work, such as additional adjustmentof the amount of refrigerant, replacement of components of a controlboard, and maintenance and inspection of pipe connections or wireconnections. Dangerous work outside the building can be avoided.

As illustrated in FIGS. 3 and 4, the air-sending-device chamber insidethe outdoor unit 1 is divided into the upper and lower compartments bythe second divider 21 as described above. A first air passage 37 inwhich the heat exchanger 19 and the first air-sending device 11 a aredisposed is provided under the second divider 21. A second air passage39 in which the second air-sending devices 11 b are disposed is providedabove the second divider 21.

As illustrated in FIG. 4, the outdoor unit 1 is connected through therefrigerant pipe 45 to the indoor unit 50 that supplies cooling energyor heating energy to the indoor space 29. For example, when therefrigeration cycle apparatus is an air-conditioning apparatus, in thecooling operation, low-temperature and low-pressure two-phaserefrigerant is supplied from the outdoor unit 1 to the indoor unit 50through the refrigerant pipe 45, the refrigerant exchanges heat withindoor air in an indoor side heat exchanger in the indoor unit 50, andcooling energy is supplied to the indoor space 29. In the heatingoperation, high-temperature and high-pressure gas-phase refrigerant issupplied from the outdoor unit 1 to the indoor unit 50 through therefrigerant pipe 45, the refrigerant exchanges heat with the indoor airin the indoor side heat exchanger in the indoor unit 50, and heatingenergy is supplied to the indoor space 29. Although the indoor unit 50is constructed as a ceiling-embedded indoor unit in FIG. 4, the indoorunit 50 may be constructed as, for example, a floor-standing indoorunit. Furthermore, a plurality of the indoor units 50 may be disposed inthe indoor space 29.

A flow of air to be subjected to heat exchange in the outdoor unit 1 ofa refrigeration cycle apparatus when the outdoor unit 1 is being drivenwill be described below. In FIGS. 3 and 4, the air flow during drivingof the outdoor unit 1 of a refrigeration cycle apparatus is indicated byopen block arrows denoted by reference signs A, B, and C.

When the outdoor unit 1 is driven, the first air-sending device 11 a isdriven and rotated, so that outdoor air is caused to pass through thefirst air passage 37 in the outdoor unit 1 as indicated by referencesign A. The outdoor air then passes through the heat exchanger 19. Whilepassing through the heat exchanger 19, the outdoor air exchanges heatwith the refrigerant flowing inside the heat exchanger 19. The airsubjected to heat exchange in the heat exchanger 19 is discharged fromthe first vent 9 a disposed in the first front panel 3 to theexternal-wall internal space 27. The rotation of the second air-sendingdevices 11 b causes the air discharged to the external-wall internalspace 27 to flow in the external-wall internal space 27 as indicated byreference sign B. The air is then sucked into the second air passage 39in the outdoor unit 1 through the second vents 9 b disposed in the firstfront panel 3. The rotation of the second air-sending devices 11 bcauses the air sucked through the second vents 9 b to be discharged fromthe air outlets 23 disposed in the first rear panel 15 as indicated byreference sign C.

As described above, the outdoor unit 1 of a refrigeration cycleapparatus according to Embodiment 1, which is installed in theexternal-wall internal space 27 of a structure, such as a building,includes the casing 1 a, the heat exchanger 19 accommodated in thecasing 1 a, the first air-sending device 11 a that causes air to passthrough the heat exchanger 19 and discharges the air to theexternal-wall internal space 27, the second air-sending devices 11 bthat suck the air discharged to the external-wall internal space 27 bythe first air-sending device 11 a and discharge the air to the outsideof the structure, and the divider that is the second divider 21 thatdivides an inside of the casing 1 a into the first air passage 37 inwhich the heat exchanger 19 and the first air-sending device 11 a aredisposed and the second air passage 39 in which the second air-sendingdevices 11 b are disposed.

In Embodiment 1, the air subjected to heat exchange in the outdoor unit1 is discharged to the external-wall internal space 27 through the firstair passage 37. The air discharged to the external-wall internal space27 is discharged to the outside of the structure through the second airpassage 39 separated from the first air passage 37 by the second divider21. In Embodiment 1, it is unnecessary to provide an air passage fordirecting the flow of air subjected to heat exchange in the oppositedirection in the outdoor unit 1. Thus, the outdoor unit 1 can ensurequietness and can be reduced in size. In addition, the flow of airsubjected to heat exchange does not stagnate inside the outdoor unit 1.This configuration leads to improvement in performance of the outdoorunit 1, thus enhancing the stability and reliability of the outdoor unit1 during operation. With the configuration in Embodiment 1,consequently, the outdoor unit 1 of a refrigeration cycle apparatus canensure quietness and achieve both reduction in size and improvement inperformance.

In addition, as the flow of air subjected to heat exchange does notstagnate inside the outdoor unit 1 of a refrigeration cycle apparatusaccording to Embodiment 1, the rotation frequency of the firstair-sending device 11 a can be reduced, resulting in a reduction inenergy consumption of the outdoor unit 1.

In the outdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 1, the second air passage 39 can be located above the firstair passage 37. Such a configuration can reduce or eliminate a shortcircuit phenomenon in which air discharged from the second air passage39 to the outside of the structure is again sucked into the first airpassage 37.

In the outdoor unit 1 of a refrigeration cycle apparatus according toEmbodiment 1, the casing 1 a can include a service panel exemplified bythe first front panel 3 or the second front panel 5 disposed on the sideof the indoor space of the structure. In some cases, the outdoor unit 1has to be installed in the external-wall internal space 27 of theexternal wall 25 that divides the indoor space 29 from an outdoor space,because no place cannot be prepared to install the outdoor unit 1. Insome cases, for reasons of appearance of a structure, the outdoor unit 1has to be installed in the external-wall internal space 27 of theexternal wall 25 that divides the indoor space 29 from the outdoorspace. The above-described configuration allows access to theexternal-wall internal space 27 from the indoor space 29 and enablesinstallation of the outdoor unit 1 and maintenance work for the outdoorunit 1, such as maintenance and inspection, when the outdoor unit 1 hasto be installed in the external-wall internal space 27 of the externalwall 25 that divides the indoor space 29 from the outdoor space.Consequently, this configuration can enhance the working efficiency ofmaintenance of the outdoor unit 1.

Embodiment 2

Embodiment 2 of the present invention will be described with referenceto FIGS. 5 and 6. FIG. 5 is a schematic front view illustrating anexemplary structure of an outdoor unit 1 of a refrigeration cycleapparatus according to Embodiment 2. FIG. 6 is a schematic rear viewillustrating the exemplary structure of the outdoor unit 1 of arefrigeration cycle apparatus according to Embodiment 2.

Embodiment 2 relates to a modification of Embodiment 1 described above.As illustrated in FIG. 5, the outdoor unit 1 has an internal space thatis divided into upper and lower compartments by a second divider 21. Thelower compartment of the internal space of the outdoor unit 1 is furtherdivided into left and right compartments by a first divider 7.

The lower right compartment of the internal space of the outdoor unit 1is covered by a second front panel 5. The lower right compartment servesas a machine chamber accommodating, for example, a compressor. Asillustrated in FIG. 6, the rear of the machine chamber is covered by asecond rear panel 17.

The lower left compartment of the internal space of the outdoor unit 1is covered by a third front panel 55 having a first vent 9 a. The lowerleft compartment accommodates a first air-sending device 11 a. The lowerleft compartment of the internal space of the outdoor unit 1 correspondsto the first air passage 37 in Embodiment 1 described above. In FIG. 5,the lower left compartment accommodates one first air-sending device 11a. As illustrated in FIG. 6, the lower left compartment of the internalspace of the outdoor unit 1 further accommodates a heat exchanger 19disposed on the side of the rear of the outdoor unit 1.

The upper compartment of the internal space of the outdoor unit 1 iscovered by a fourth front panel 60 having second vents 9 b. The uppercompartment accommodates second air-sending devices 11 b. The uppercompartment of the internal space of the outdoor unit 1 corresponds tothe second air passage 39 in Embodiment 1 described above. In FIG. 5,the upper compartment accommodates three second air-sending devices 11b. As illustrated in FIG. 6, the rear of the upper compartment of theinternal space of the outdoor unit 1 is covered by a first rear panel 15having a plurality of air outlets 23.

As described above, the outdoor unit 1 of a refrigeration cycleapparatus according to Embodiment 2 is configured such that a casing 1 aincludes the machine chamber that is a space that accommodates acompressor 13, and the second air passage is disposed above the machinechamber. Such a configuration allows an increase in the number of thesecond air-sending devices 11 b that can be disposed in the second airpassage 39, thus enhancing the efficiency with which air subjected toheat exchange is discharged.

Other Embodiments

The present invention is not limited to the embodiments described above.Various changes and modifications of the present invention may be madewithout departing from the spirit and scope of the present invention.For example, the embodiments described above are also applicable torefrigeration cycle apparatuses other than an air-conditioningapparatus, for example, a heat pump water heater.

1. An outdoor unit of a refrigeration cycle apparatus, the outdoor unitbeing to be installed in an external-wall internal space of a structure,the outdoor unit comprising: a casing; a heat exchanger accommodated inthe casing; a first air-sending device configured to cause air to passthrough the heat exchanger and discharge the air to the external-wallinternal space; a second air-sending device configured to suck the airdischarged to the external-wall internal space by the first air-sendingdevice and discharge the air to an outside of the structure; and adivider that divides an inside of the casing into a first air passageand a second air passage, the heat exchanger and the first air-sendingdevice being disposed in the first air passage, the second air-sendingdevice being disposed in the second air passage.
 2. The outdoor unit ofa refrigeration cycle apparatus of claim 1, wherein the second airpassage is located above the first air passage.
 3. The outdoor unit of arefrigeration cycle apparatus of claim 2, wherein the casing includes amachine chamber that serves as a space accommodating a compressor, andwherein the second air passage is located above the machine chamber. 4.The outdoor unit of a refrigeration cycle apparatus of claim 1, whereinthe casing includes a service panel disposed on a side of an indoorspace of the structure.